The present invention relates generally to electronic locks where the outside handle is deactivated unless power is supplied to the lock.
Electronic security locks for doors are known. Typically, the exterior handle of the security locks remains deactivated unless power is supplied to the lock system from an operator inside the building. For example, many apartment buildings include an electronic security lock that must be activated by a tenant or security guard disposed inside the building before someone outside the building can open the door. The mechanisms by which these locks operate can vary. In one design, the locking mechanism is disposed in the door jamb and is released when current is supplied to the door jamb This design is disadvantageous because it can be forced open upon the application of a significant force at the door jamb.
Many hotels and apartment buildings employ a mortise lock which includes an outer hub mounted onto the shaft connected to the outside handle and another inner hub mounted onto the shaft connected to the inside handle. The hub connected to the inside handle shaft is the hub that engages the latch bolt mechanism upon rotation. This will occur when the inside handle is rotated or when the outside handle is rotated and the outer hub is linked to the inner hub. This linking occurs only when the lock is activated.
Activation of mortise lock hubs is typically achieved using an electric motor which moves a connecting part that links the two hubs together so that rotation of the outer handle results in rotation of both the outer hub mounted to the outer handle shaft and rotation of the inner hub mounted onto the inner handle shaft. The employment of a motor or a significant amount of moving parts is problematic in terms of both cost of manufacture, maintenance and reliability.
Accordingly, there is a need for an electronic security lock, particularly of the mortise lock type, that is less expensive to manufacture, maintain and that is more reliable.